It is extremely commonplace for electrical components, such as switches, to be recessed into walls. In industrial premises where cleanliness is paramount, such as the food and beverage preparation and pharmaceutical industries, it is particularly important that all surfaces and switches are easily cleaned and more preferably provide a substantially waterproof seal protecting the electrical components within the enclosure from any engagement with water.
FIG. 1 shows an example of a waterproof enclosure of the prior art. The enclosure 10 is recessed into an opening 12 in a wall 14 covered with tiles 16 which are stuck to the wall 14 using a layer of adhesive 18. The enclosure 10 includes a metal box 20 which is entirely contained within the opening 12 and is generally fixed to a surface of the opening 12 by an adhesive or a screw (not shown) extending in to wall 14. The box 20 has a pair of lugs 22 which have threaded apertures to receive bolts 24. The bolts extend through a front plate 26 which carries a component such as a button switch 28. The bolts 24 pull the front plate 26 towards the metal box 20 and a bead of sealant 30 extends around the front plate 26, adjacent its perimeter, thereby sealing the enclosure relative to the wall in preventing water from entering the enclosure.
The installation of this enclosure 10 will only provide a waterproof seal if the bead of sealant 30 is correctly applied. A number of factors affect the quality of this seal including the quality of the bead of sealant applied by the installer, which is at least in part dependent upon the installer's experience. Furthermore, over tightening of the bolts 24 can lead to damage to the seal 30, distortion of the front plate 26 or dislodging of the box 20 from its fixing to wall 14 making the whole enclosure 10 vulnerable to removal from the opening 12. It is also the case that to the wall by the sealant. As a result, if a pulling force is applied to the enclosure it can become partially dislodged from the wall thereby damaging the seal. Furthermore, if the cover plate is removed, for example for inspection or maintenance, the sealant 30 must be completely removed from the front plate 26 and a new bead of sealant applied.
Preferred embodiments of the present invention seek to overcome the above described disadvantages of the prior art.